NSA Device to identify SA deployed in some areas

5G NR
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61

So the only way to know whether UE supports SA would be to try and get it attached to an SA network?

62

Ideally LTE RAT attach should have UE capability request for other RATs as well.

63

Band combo for CA, ENDC = EUTRA+NR, SA = NR only bands as well, supporting both, EUTRA+NR & NR only combos.

64

So if we do an NR RAT only enquiry on the NSA UE and it replies with some band information.
Does that mean it supports SA?

65

NR RAT rat only enquiry will be done only by SA network. Is this True?

66

Lets say we have a simulator.
Through that if we want to check if UE supports SA, is this the way to do it?

67

At the first place if you have a UE in hand, I will look its specs to check if it supports SA.
Back to my first answer is the easiest way. :grin:

68

Ideally, Yes.
As if UE doesn’t support SA, it wouldn’t send NR only Band combos.

69

Another easy way is this. :wink:

70

Haha, that beats all other ways hands down :wink:

71

But I need to have UE specs for that. :grin:

72

That’s true…but Google is alive. :joy:

73

Only if was giving specs development board! :innocent:

74

Haha, See here this is the specs for the device I use - Samsung Galaxy S20+ with Qualcomm X 55 5G modem.

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75

True.
But the dev board caps seems to be quite dynamic!
So I need to be sure if what the device is currently reporting.

76

As I mentioned before, the existence of SIB1 can be known from the value of kSSB ( 1 bit from PBCH and 4 bits from MIB)
The pdcch-ConfigSIB1 is more related to coreset#0 which is mandatory for SA and optional for NSA

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77

I think that if UE is just NSA supporting device, under cocerage of 5G SA only, UE can measure PBCH RSRP only, but can not attach to 5G SA network because:

1, sib1 of 5g SA is always sent over 5G air interface, while sib1 of 5g NSA is sent to ue via 4G air interface. So, NSA UE may not read sib1 of 5G SA.

2, SA is contension based random access while NSA is contension free RA. NSA UE always need network send it a dedicated preamble but SA gnb not send dedicated preambles.

3, authentication method of 5G is little different with 4G. NSA UE is authenticated in 4G network, but may not successfully authen in 5G.

78

Guys,

To end this: did we figure out (in our prev discussions) whether SA and NSA use the same gNB?

79

Using MIB message.
If pddch-Config SIB1 is configured in MIB then it’s a SA capable NW.

80

We had a DT with SA-NSA capable mode in NSA area, my device got SA MIB & SIB but AMF registration failed stating “N1 mode not allowed”.